Editing Class variable (section)

==Examples==

=== C++ ===
<syntaxhighlight lang="cpp" line="1">
struct Request {

    static int count;
    int number;

    Requestobject() {
        number = count; // modifies the instance variable "this->number"
        ++count; // modifies the class variable "Request::count"
    }

};

int Request::count = 0;
</syntaxhighlight>

In this C++ example, the class variable <code>Request::count</code> is [[increment operator|incremented]] on each call to the [[constructor (computer science)|constructor]], so that <code>Request::count</code> always holds the number of Requests that have been constructed, and each new Request object is given a <code>number</code> in sequential order. Since <code>count</code> is a class variable, there is only one object <code>Request::count</code>; in contrast, each Request object contains its own distinct <code>number</code> field.

Also note that the variable <code>Request::count</code> is initialized only once.

=== Python ===
<syntaxhighlight lang="python">
class Dog:
    vertebrate_group = 'mammals' # class variable

dog_1 = Dog
print(dog_1.vertebrate_group) # accessing the class variable
</syntaxhighlight>In the above Python code, it does not provide much information as there is only class variable in the Dog class that provide the vertebrate group of dog as mammals. In instance variable, you could customize your own object (in this case, dog_1) by having one or more [[instance variable]]s in the Dog class.